Make sure that the account you are login into have the rights to view the sources remotely. Test with the admin account. Also, if you come from the WAN side you need to port forward the router. Test on the LAN first.To summarize: start with admin account on LAN. -Henrik

Thanks! The web client is the most straight forward so either your ISP for the mobile blocks port 8100 or make sure that the router port forward to correct IP. Some routers can only work with a static IP on the computer. Use another port like 3432 or something and in the router redirect also the port from 3432 to 8100 if that is possible. Do you have a static public IP or use a DDNS service?-Henrik

I am out of ideas for the moment. It all works on the LAN so the change is to go to public IP. You haven´t enabled SSL? Can you test with another phone? OK, restart the router! That can hang sometimes. My did.